Grassley says officials must be held accountable for scandal.

Sen. Chuck Grassley, R-Iowa, ranking member of the Senate Judiciary Committee, is satisfied with the Secret Service response to his inquiries about alleged misconduct of Secret Service agents in Colombia, but wants a better response from the White House.

In an April 20 letter to Secret Service Director Mark Sullivan and Inspector General Charles Edwards, Grassley asked about additional details concerning overnight visitors and the involvement of White House communications and advance staff. Grassley has been one of the most outspoken lawmakers on the issue, which implicated 12 Secret Service members and 12 military service members in alleged misconduct during their stay in advance of President Obama's visit to Cartagena, Colombia last month. Just last week, Grassley said on CBS's This Morning he expects officials to be held accountable, and called for an independent investigation into the proceedings.

Sullivan's May 1 answer to Grassley's letter said that, as far as the agency was aware, the agents involved had not leaked sensitive information. Grassley released a redacted version of Sullivan's response today.

"The Secret Service has no information to suggest that sensitive information was compromised during the Colombia trip," it says, but cautions that "we would defer to the Department of
Defense and the White House on matters related to their respective personnel."

The letter also reveals that the investigation, still under way, found that only one of the officers had an overnight guest -- a significant detail, as Grassley and other lawmakers have raised the possibility of overnight guests potentially drawing sensitive information out of agents and compromising the president's security.

Sullivan has briefed lawmakers on the ongoing investigation over the past few weeks, and Grassley said in a statement that he "appreciate[s] the Secret Service's transparency in response to Congress." But as Sullivan was unable to answer most of his questions surrounding White House personnel, Grassley said he was still hoping for more information from the White House.

"Since the Secret Service did not request the records of the White House personnel, an open and transparent response from the President's Counsel is even more imperative," he said. "Unfortunately, more than a week after my inquiry, I've yet to hear from anybody at the White House."

An internal investigation at the White House revealed, according to White House Press Secretary Jay Carney, "no indication of any inappropriate behavior or misconduct" by White House staff.